In the above-mentioned transfer gear provided with a speed change gear function which allows a driver to select a low-speed high-power position or a high-speed low-power position and a differential function which can prevent a tight-corner braking phenomenon produced in vehicle turning, at least one change gear and at least one control differential gear are required.
The above transfer apparatus provided with two functions are large in size and heavy in weight as compared with a transfer apparatus provided with either one of the speed change gear and central differential gear. Further, there exist other drawbacks such that the number of gears increases, and the changing-over mechanism is complicated.